It is known that inorganic sulfur compounds such as COS and CS.sub.2 may be removed from process gases in accordance with physical and chemical processes by washing solutions or by adsorption. A summarizing review of these known processes is to be found in R. D. Stoll and S. R/o/ per, "Erd/o/ l und Kohle," Volume 35, pages 380-385 (1982). These processes are used mainly for the purification of natural gas (sour gas) containing acidic sulfur compounds, but are also suitable for the removal of sulfur compounds from process gases such as flue-gases, Claus tail gases and gases resulting from the refinement of coal. The inorganic sulfur compounds can be removed from the gas, for instance, physically, with the aid of washing solutions containing N-methyl pyrrolidone, propylene carbonate or propyl ethylene glycol-dimethyl ether, or chemically, by transformation with basic* organic compounds (e.g. diisopropanol amine, potassium-dimethyl-aminoacetic acid, alkanol amines). The adsorption processes are carried out with the aid of adsorption agents such as Fe.sub.2 O.sub.3, activated carbon, molecular sieves, dolomite, silica gel and similar compounds. The processes mentioned above, however, are costly and cumbersome. FNT *"basic organic compounds" indicates organic compounds which react in an alkaline manner.